Pump



Jan 7 1947' '.c. c. WILLIAMS 2,413,935

PUMP

Filed Ju1y's,`1944 4 sheets-sheet 2 c. c. WILLIAMS Filed July 3, 1944 {Shoots-Shed 3 JUL 7, 1947 c. c. WILLIAMS 2,413,935

' PUMP Filed July 3, 1944 4 Shasta-Sheet 4 APatented Jian.) 7; l1,947'

V UNITED STATES PATENT OFFICE PUMP' calvin c. williams, Philadelphia, Paf Application July 3, 1944, Serial No. 543,253

(c1. ics-iii) 1 claim. l

This invention relates Ito an improved rotary pump and while being especially intended for use as a blower in pumping gaseous fluids, such as air,

may also be used with equal facility for pumping liquids.

Among other objects, the invention seeks to provide a pump wherein a gain in displacement will be had over a comparable pump having a cylindrical casing of an internal diameter equal to the distance between aligned blades from tip to tip. K

it further object of the invention is to provide a pump wherein lthe tips of the blades will be caused to follow a somewhat `elliptical path` thereby to obtain a greater displacement of the pump as compared with like blades travelling in a circular path.

Still another'object of the invention is to provide a pump wherein the pump casing will, throughout -the major portion of its interior, be of somewhat elliptical contour conforming to the travel of the tips of the blades, but wherein the somewhat elliptical inner surface of the casing will .be interrupted at one point by an arcuate seat accommodating the periphery of the rotor and cooperating therewith to form a working seal between Ithe inlet and the outlet of `the pump.

A further object of the invention is to providev a pump wherein substantially no friction will occur between the tips of the blades and the casing so that the pump may be operated at high speeds and adapting the structure for use as a prime mover, if so desired.

And the invention seeks, as "a st-ill further object, to provide a pump wherein the discharge pressure thereof may be varied.

Other and incidental objects will appear during the ensuing `description of the invention, and in the drawings:

Figure 1 is a vertical longitudinal sectional vview through my improved pump.

Figure 2 is a transverse section on the line 2-2 of Figure 1. Y

Figure 3 is a transverse section on, the line 3--3 'of Figure 1.

Figure 4 is a transverse section on the line 4 4 of Figure 1. l

Figure 5 is a detail plan view of the rotor.

Figure 6 is a fragmentary perspective view of one of the blades.

Figure '7 is a detail section on the line 'I-l of Figure l.

Figure 8 is a detail perspective of the fixed crank shaft employed. l

Figure 9 is a diagrammatic view showing the somewhat elliptical interior of the easing and the arcuate rotor seat.

Figures lil, 11 and'12 are diagrammatic views air, for instance, and varying the discharge pres sure of the pump.

Detachably nxed to the casing it at one end is an end cap` it having a hub it, and detachably iixed to the casing at its opposite end is an end cap il having a hub lll, Extending within .the casing from the cap it is a xed crank shaft i9, seen in detail in Figure 8 9i the drawings, and,l as will .be observed, this shaft is provided at one end with a long terminal 2t While at the opposite end of the shaft is a short terminal 2i aligned with the terminal it. The shaft is further provided with spaced cranks 22 having aligned pins 2t, while the outer ends of said pins are reduced to forni necks 2t. VRigidly iixed to the hub lli of the end cap l5' is a detachable end plate 2t having a sleeve tti through which the terminal 2t of the shaft it extendsy and locking the shaft in said sleeve is a key 2li. The shaft Will .thus be rigidly supported to extend in fixed position within the casing ill.

Mounted to turn about the axis of the shaft I9 is a hollow cylindrical rotor 2t which, as seen in Figures 2 and 3 of the drawings, is provided at quadrantly spaced points with chordal thickened portions 29 having slots 30 therethrough, and bracing the rotor internally are medial Webs 3|. Formed on the rotor at one end is a hub 32 having a sleeve 33 which freely but closely surrounds the terminal 2li of the shaft I9, and formed on the rotor at its opposite end is a somewhat larger hub 3ft having a sleeve 35, the outer end of which lies ush with the terminal 2 lA of the shaft. Fixed within the hub i6 of the cap l5 is a bearing 36 which surrounds the sleeve 33 and rotatably supports the rotor at one end` and fixed within the sleeve 35 is a bearing 3l which surrounds the terminal 2i of the shaft I9 and rotatably supports the rotor at its opposite end. Y

1t is now -to be noted that the rotor 28 is split at the plane of one pair of the slots 30 into like complemental mating sections so that the rotor maybe assembled about the pairs of blades later to be described, and formed on the hubs 32 and 34 of the rotor are mating bosses 38. Engaged through said bosses are cap screws 39 detachably securing the sections of the rotor together.

Extending through the hub i8 of the end cap l1 of the casing l0 is a drive shaft id aligned with the axis of the shaft I9, and formed on the drive shaft is a head M which snugly fits over the outer end of the sleeve 35 of the hub 3 of the rotor 28 and seats against said hub. Detachably securing the head to the hub are cap bolts t2. Fixed in the hub i8 is a bearing d3 which rotatably supports the drive shaft, and detachably secured to the outer end of said hub is an end plate dll surrounding the shaft. Thus, power may be applied to the shaft Il@ for turningr the rotor. Formed through the terminal 29 of the shaft I9, as best seen in Figure 8 of the drawings, is a duct d so that oil may be introduced into the casing, and disposed about said terminal and about the shaft d@ are washers it of felt or the like to prevent leakage.

Mounted upon the crank pins 23 of the shaft is are bearings d1, and in this connection it isto be observed that. the outer side plates of the cranks 22 of the shaft are beveled at their ends so that the bearings may be slipped over the terminals of the shaft and over said plates to be thus installed. Fitting the necks 2li of the pins are sectional stop collars d8 blocking outward displacement of the bearings, and detachably securing'said collars in position are split spring rings 45.*.. Fitting the outer race rings of the bearings are square crossheads 59. y

Cooperating with the crossheads 59 are pairs of oppositely disposed blades 5l which are slidably received through the slots 30 of the rotor 28, and, as will be noted, the thickened portions 29 of the rotor will provide a correspondingly wide bearing area between the walls of said slots and the blades.. FormedV on the blades at their inner edges, as particularly seen in Figure 6, are mating yoke sections 52 which straddle the shaft I9, and detachably connecting said sections are bolts 53, it being observed, as best brought out in Figure 1, that the yokes of one pair of blades are staggered with respect to the yokes of the other pair of blades. The blades of each pair of blades are thus rigidly united to form a solid unit so that each blade of each pair will balance the other blade of each pair and tend to counteract the effect of centrifugal force on the blades. Thus, the blade units are balanced and may be rotated at high speed. Formed on the inner edges of the blades at the ends thereof are saddle plates 54. which slidably fit against the edges of the crossheads 50 to coact therewith and connect the blades with said crossheads.

Attention is now directed to Figure 9 of the drawings. A circle is shown at 55. 'Ihis circle has a center 56 which represents the axes of the crank pins 23 of the shaft I9. A point 51 represents the axis of the shaft and, consequently, the

center of rotation of the rotor, indicated on the diagram by a circle 58, The distance between the points 56 and 51 in a straight line is the distance which the bearings 41 are eccentric with respect to the center of rotation of the rotor and is the diameter of a circle 59. Struck from points on this circle, say fifteen degrees apart more or less, as suggested by the radial lines on the diagram, is a somewhat elliptical curve indicated at 60, which curve coincides with the circle 55 at the area designated 6|. The curve 60 represents the contour of the inner surface of the casing l0, except at that area represented between the points 62 and 63 on the diagram. Between the points 52 and 63, the inner surface of the casing is cut away to form an arcuate seat indicated at 8d.,

This seat is of' substantially the same radius, or

slightly more, say a few thousandths or so, than the radius of the periphery of the rotor 23 and 5 is struck from the point 51 as a center. Accord ingly, said seat is curved to fit the periphery of the rotor with which it coacts to form a working seal between the rotor and the casing throughout a relatively wide arcuate area lying between the inlet i2 and the outlet i3 of the casing it), For the purposes of this disclosure, I have indicated the area of the seal as extending for thirty degrees between the points G2 and E53 but as will be understood, the area of the seal may, oi' course, be varied. It is important, however, to provide, instead of straight line contact as would otherwise occur between the rotor and casing in the absence of the seat ed, a relatively wide seal since, as will be explained, the tips of the blades 5l will follow the curve Gil; between the points @2 and E33 so that said seal must alone serve to cut oii communication between the inlet and the outlet of the casing.

Referring now to Figures 10, 1l and l2 of the drawings, reference letters will be used to avoid confusion with the reference numerals of the other gures of the drawings. One of the crossheads 59 is indicated'at A and the top and bottom edges thereof, as viewed in Figure 10, at B and C respectively. A blade unit comprising one pair of the blades 5i is indica-ted at D, one pair of the saddle plates 5d thereof at E, and the top and bottom edges of one of the yokes between the blades of said unit at F and G respectively. The rotor 28 is indicated at H and an arbitrary point thereon at I. The points 56 and 51 as well'as the circle 59, as used in Figure 9, remain the same in Figures 10, 1l and 12 and are so designated. Explanation of the movement of one pair of blades will suice for both pairs of said blades.

Assuming now that the blades D stand in the horizontal position shown in Figure 10, it will be seen that the longitudinal center of the blade uni-t is disposed at the point 51 on the'circle 59 45 while the plates E are at the edge B of the crosshead A. As the rotor H turns, the plates E of the blade unit will, by the action of the rotor on the blades, be shifted along the crosshead while the longitudinal center of the blade unit will travel around the circle 59 until, when the point 1 on the rotor has traveled ninety degrees and the blades D have reached a vertical position, as shown in Figure 11, the longitudinal center of the blade unit will be at the point 56 on said circle,

so that the plates E will be at a middle position on the crosshead,

As the rotor H further turns and the point I on the rotor has traveled one hundred eighty degrees and has reached'the position shown in Figure 12, the longitudinal center of the blade unit will have completed its travel from the point 56 around the circle 59 to again lie at the point 51.

As will be observed, the edge B of the crosshead,

A is now at the bottom and the edge C at the top while the edge F of the yoke of the blades is at the bottom and the edge G at the top. Thus,l during one hundred eighty degrees of revolution of the rotor H, the longitudinal center of the blade unit has travelled completely around the circle 59 while the blades have been shifted from one end to the other of the crosshead, it being observed in Figure 12 that thev plates E are at the edge C of the crosshead, The cycle will, of course, be repeated during the next one hundred eighty degrees of revolution of the rotor.

' during each one hundred eighty degrees of revolution of the rotor, a path which may be termed somewhat elliptical, which is the curve 60 shown in Figure 9. The tips of the blades will accordingly follow the somewhat elliptical contour of the inner surface of the casing without friction therebetween. Thus, at the area of theseat B4, the tips of the blades will not, as previously mentioned, contact said seat due to the fact that the seat is on a radius of the point 5l and interrupts y the somewhat elliptical inner surface of the casing for the width of the seat. As will now also be apparent, the pump will, due to the somewhat elliptical inner contour of the casing, have a greater capacity than a similar pump having a casing of the same size but of cylindrical inner contour.

Having thus described my invention, what I claim is:

A rotary pump including a casing, end caps fixed to the casing and provided with hubs, an end plate carried by the hub of one of said caps, a stationary crank shaft extending into the casng,`said shaft being fixed at one end to said plate and being free at its opposite end, a rotor surrounding the shaft and provided with end sleeves, a bearing ixed in the hub of said end cap to coact with one of said sleeves externally thereof and journaling the rotory at one end, a bearing xed to the free end of said shaft to coact with the other of said sleeves in-ternally thereof and journaling the rotor at its opposite end, a i

drive shaft journaled through the hub of the other of said end caps and connected to the rotor at the free end of the crank shaft, blades slidably 'received through the rotor tocoact with the casing, and means rotatably mounting the blades on said crank shaft eccentrlcally of the` rotor.

CALVIN C. WILLIAMS. 

